Movable magnetic shunt transformer



1943- H. A. w. KLINKHAMER 2 MOVABLE MAGNETIC SHUNT TRANSFORMER Filed May3, 1946 WM/aw ATTORNEY Patented Oct. 5, 1948 UNITED. STATE MOVABLEMAGNETIC SHUNT TRANSFORMER Hendrik Abraham Wijnand Klinkhamer,Eindhoven, Netherlands, assignor, by mesne assignments, to HartfordNational Bank and Trust Company, Hartford, Conn., as trustee ApplicationMay 3, 1946, Serial No. 666,950

In the Netherlands September 17, 1942 Section 1, Public Law 690, August8, 1946 Patent expires September 17, 1962 3 Claims- (Cl. 171-119) Thisinvention relates to a transformer, which is controllable by means ofmovable magnetic shunts and consists of two shell transformers inScott's arrangement and is more particularly characterized in that thetransformer cores are assembled into a five-limb core having an unwoundmiddle core and two unwound outer cores, shunts being provided solely inthe two windows adjoining the middle core in a direction normal to thelamellation of the core, which shunts are movable and are so to befastened, by means of a clamping device, as to be free from vibration.

When making use of the Scott circuit the advantage known" per se issecured of obtaining a three-phase output voltage from a two-phase inputvoltage, or conversely. The contruction of a 'five-iimb core having anunwound middle limb and two unwound outer limbs from two shelltransformers yields a very simple contruction that can be manufacturedat a low cost. The use of a magnetic shunt solely in each of the windowsadjoining the middle limb by means of a total number of only two movablemagnetic shunts capable of being clamped in installations not having anexaggerated control range, for instance, in cinema rectifiers or thelike yields sufficient possibilities of control. Since only two shuntsare shifted and clamped for simultaneous control of the three phasesonly a few running surfaces in the paths of--the shunts need be finishedwith the required precision,- whilst the devices for moving and clampingthe shunts may have a simple construction.

In this respect it is still pointed out that the unwound middle core mayconsist of two separated parts each of which forms part of a separateshell transformer. However, it is advisable that the middle limb shouldbe constructed as a .unit, as shown in the drawing.

The displacing device consists, in a manner known per se, .of ayoke-shaped coupling piece which is connected at its ends to the shuntsand pressing piece are provided in such manner that clamping of theshunts takes place by moving the pressing piece in a longitudinaldirection of the unwound middle core.

The invention will be more fully explained by reference to theaccompanying drawing in which:

Fig. 1 is a plan view of a transformer according to the invention with afurther feature of the invention illustrated in a sectional view; and

Fig. 2 is a section of the transformer according to the invention .takenalong the line A-A of Fig. 1.

Referring more particularly to Fig. 1 of the drawing, the transformerconsists of two shell transformers I and 2 whose windings 3, l and l, 8are connected according to Scott. The transformer cores are united toform a flve-llmbed core having an unwound middle core I and two unwoundouter cores 8, 9. Two movable shuntslo, H, which are so to be secured asto be free from vibration by means of a clamping device, are solelyprovided in the two windows I2, ll-adjoining the middle core 1.

As can be seen from Fig. 2, the shifting device consists of a handwheelwith a screw spindle I5 which, by means of the nut l8 and the fasteningplates I], bring the shunts l0 and II into the desired position in adirection normal to the direction of lamellation of the cores, thespindle 80 I5 resting on the housing iii of the clamping device.

The latter consists of two wedge-shaped members I9, 20 between which isprovided anadjustable cuneiform pressing piece 2|. The pressing piece 2!is movable, by means of a screw spindle and handwheel oranother-suitable device (for the sake of simplicity not represented inthe drawing) in a longitudinal direction'of the core I, i. e., into thedirection of the arrow points of the arrow 40 22, as a resultof whichthe wedge-shaped members l9 and 20 clamp the shunts Ill and l I againstthe wound limbs of the transformer in such manner as to be free fromhumming. Consequently the screw spindle extends parallel with theunwound middle core I and may be fastened thereto,

since sufiicient space is available here.

What I claim. is: 1.- A transformer which is controllable means ofmovable magnetic shunts comprising two shell transformers in Scottsarrangement, in which the transformer cores are united to form afive-leg core'having an unwound middle core and two unwound outer cores,movable magnetic shunts being provided solely in the two windows 5adjoining the middle core in a direction normal to the lamellation ofthe core, and a clamping device securing said shunts to said transformerin a vibration-free manner, said clamping device comprising twowedge-shaped members bearing on said shunts, a. cuneiform pressingmember between said wedge-shaped members, and means to position saidcuneiform pressing member between said shunts to clamp said shunts tosaid transformer.

2. A transformer as claimed in claim 1, in which the wedge-shapedmembers and the conical'pressing piece are provided in such manner thatclamping of the shunts takes place by shiftin: the pressing piece in a.longitudinal direction of the unwound middle core.

nnrmnncns ormn The following references are of record in the file ofthis patent:

' UNITED STATES PATENTS Name Date Klinkhamer Aug. 31, 1937 Number

